Database.PostgreSQL.PQTypes.FromSQL

Documentation

class (PQFormat t, Storable (PQBase t)) => FromSQL t where

Class which represents "from SQL (libpqtypes) type to Haskell type" transformation.

Associated Types

type PQBase t :: *

Base type (used by libpqtypes).

Methods

fromSQL

Arguments

:: Maybe (PQBase t)

base value (Nothing if NULL was delivered)

-> IO t

Convert value of base type to target one.

Instances

FromSQL Bool

FromSQL Char

FromSQL Double

FromSQL Float

FromSQL Int16

FromSQL Int32

FromSQL Int64

FromSQL Word8

FromSQL String

Assumes that source C string is UTF-8, so if you are working with a different encoding, you should not rely on this instance.

FromSQL ByteString

FromSQL ByteString

FromSQL Text

Assumes that source C string is UTF-8, so if you are working with a different encoding, you should not rely on this instance.

FromSQL UTCTime

FromSQL instance for ZonedTime doesn't exist because PostgreSQL doesn't provide zone offset information when returning timestamps with time zone in a binary format.

FromSQL Text

Assumes that source C string is UTF-8, so if you are working with a different encoding, you should not rely on this instance

FromSQL LocalTime

FromSQL TimeOfDay

FromSQL Day

FromSQL Interval

FromSQL XML

FromSQL t => FromSQL (Maybe t)

FromSQL (JSONB ByteString)

FromSQL (JSONB ByteString)

FromSQL (JSONB Value)

FromSQL (JSON ByteString)

FromSQL (JSON ByteString)

FromSQL (JSON Value)

CompositeFromSQL t => FromSQL (Composite t)

FromSQL (Binary ByteString)

CompositeFromSQL t => FromSQL (CompositeArray2 t)

FromSQL t => FromSQL (Array2 t)

CompositeFromSQL t => FromSQL (CompositeArray1 t)

FromSQL t => FromSQL (Array1 t)